Review of water treatment technologies for PFAS from a life cycle perspective, with meta-analysis of financial costs and climate impacts

Per- and polyfluoroalkyl substances (PFAS) contamination of drinking water is now a critical environmental and public health concern. Conventional water treatment is ineffective, prompting investment in solutions like granular activated carbon, ion exchange, membrane filtration, foam-fractionation and electrochemical oxidation. However, selecting appropriate technologies involves trade-offs among performance, resource use and environmental impact criteria. Our analysis aims to offer new insights into the climate impacts per gram of PFAS removed and the annual capital and operational costs per volume water treated. We also highlight critical limitations of environmental assessment of PFAS treatments, particularly regarding toxicity-related impacts, that have not kept pace with developments in life cycle assessment methodology. Our analysis synthesizes data from 17 disparate publications on PFAS treatment technologies. Emissions from innovative treatments vary widely, with climate impacts ranging from 0.1 to 70 190 kg CO 2 eq. per gram of PFAS depending on raw water PFAS concentrations. The economic analysis showed that operational costs span from $0.03/m³ to $28/m³, while capital expenditures range from $0.01 to $0.51/m³ of water treated and exhibit some economies of scale. This work also underscores the importance of using life cycle assessment and life cycle costing approaches to comprehensively evaluate PFAS removal technologies.